Magnetostrictive auditory system

ABSTRACT

Disclosed is hearing device that uses magnetostrictive materials to assist a user in hearing and comprehending sounds. Conductive coils are made with a magnetostrictive covering that can comprise a film or other coating. In addition, printed circuit boards can be used with traces that form a coil to generate a magnetic field that activates a magnetostrictive film disposed over the coil traces on the printed circuit board. Enhanced effects are achieved using these systems. Delays in the signal processing can also be introduced by varying the thickness of the magnetostrictive coverings.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of and priority to United StatesProvisional Patent Application Ser. No. 61/080,180, entitled“Magnetostrictive Auditory System” by Joan M. Burleigh, et al., filedJul. 11, 2008, the entire content of which is specifically incorporatedherein by reference for all that it discloses and teaches.

BACKGROUND OF THE INVENTION

Portable hearing devices have been very effective in assistingindividuals that have impaired hearing and/or comprehension in difficultlistening environments to more clearly hear, understand and enjoyauditory signals. Depending upon the type of impairment that anindividual may have, or the environment in which the individual may havedifficulty hearing, hearing devices may operate more efficiently withsome individuals and not as well with others. Many of the problemsassociated with hearing loss as well as comprehension of audible signalsare not well understood. A large number of factors can affect bothhearing and comprehension of various types of audible signals. As aresult, hearing devices that aid a user in hearing and comprehendingaudible signals may not be simply dependent upon amplification of theaudible signal at specified frequencies.

SUMMARY OF THE INVENTION

An embodiment of the present invention may therefore comprise a methodof assisting an individual with auditory comprehension of audiblesignals using a hearing device comprising: coating a conductive wirewith a magnetostrictive coating; forming the wire in a coil; generatingan electrical signal from the auditory signal; applying the electricalsignal to the coil that causes the magnetostrictive coating to changesize in response to the electrical signal so that the magnetostrictivecoating generates auditory vibrations to assist the individuals with theauditory comprehension of audible sounds.

An embodiment of the present invention may therefore further comprise ahearing device that assists users having impaired auditory comprehensioncomprising: a detector that detects audible signals and translates theaudible signals into an electrical signal that varies in amplitude inaccordance with the audible signals; a driver that amplifies theelectrical signal to provide an amplified electrical signal; aconductive wire formed in a coil that is connected to the driver toreceive the amplified electrical signal and generate a magnetic wave inresponse to the electrical signal that varies in amplitude in accordancewith the amplitude of the electrical signal; a first magnetostrictivecoating substantially surrounding the conductive wire that changes sizein response to the electrical signal and generates auditory vibrationscorresponding to the amplitude of the electrical signal that assist theusers in comprehending the audible signals.

An embodiment of the present invention may therefore further comprise amethod of assisting an individual with auditory comprehension of audiblesignals using a hearing device comprising: forming a coil from a printedcircuit board trace on a printed circuit board; covering the coil formedon the printed circuit board with a magnetostrictive film; generating anelectrical signal from the auditory signal; applying the electricalsignal to the coil that causes the magnetostrictive film to change sizein response to the electrical signal so that the magnetostrictive filmgenerates auditory vibrations to assist the individual with the auditorycomprehension of audible signals.

An embodiment of the present invention may therefore further comprise ahearing device that assists users having impaired auditory comprehensioncomprising: a microphone that detects auditory signals and translatesthe auditory signals into an electrical signal that varies in amplitudein accordance with the auditory signals; a driver that amplifies theelectrical signal to provide an amplified electrical signal; a coilformed from a printed circuit board trace on a printed circuit board; afirst magnetostrictive film substantially covering the coil on theprinted circuit board that changes size in response to a magnetic fieldgenerated by the amplified electrical signal that is applied to the coiland generates auditory vibrations corresponding to the amplitude of theamplified electrical signal that assist the users in comprehending theaudible signals.

An embodiment of the present invention may therefore further comprise amethod of assisting an individual with hearing an auditory signal usinga hearing device comprising: coating a conductive wire with amagnetostrictive coating; forming the wire in a coil; generating anelectrical signal from the auditory signal; applying the electricalsignal to the coil that causes the magnetostrictive coating to changesize in response to a magnetic field generated by the coil in responseto the electrical signal so that the magnetostrictive coating generatesauditory vibrations that assist the individual with hearing the auditorysignal.

An embodiment of the present invention may therefore further comprise ahearing device that assists users having impaired auditory functioncomprising: a microphone that detects auditory signals and translatesthe auditory signals into an electrical signal that varies in amplitudein accordance with the auditory signals; a driver that amplifies theelectrical signal to provide an amplified electrical signal; aconductive wire formed in a coil that is connected to the driver toreceive the amplified electrical signal and generate a magnetic field inresponse to the electrical signal that varies in amplitude in accordancewith the amplitude of the electrical signal; a first magnetostrictivecoating substantially surrounding the conductive wire that changes sizein response to the magnetic field and generates auditory vibrationscorresponding to the amplitude of the amplified electrical signal thatassist the users in hearing the auditory signals.

An embodiment of the present invention may therefore further comprise amethod of assisting an individual with hearing auditory signals using ahearing device comprising: forming a coil from a printed circuit boardtrace on a printed circuit board; covering the coil formed on theprinted circuit board with a magnetostrictive film; generating anelectrical signal from the auditory signal; applying the electricalsignal to the coil that causes the magnetostrictive film to change sizein response to the electrical signal so that the magnetostrictive filmgenerates auditory vibrations to assist the individuals with hearing theauditory signals.

An embodiment of the present invention may therefore further comprise ahearing device that assists users having impaired hearing comprising: adetector that detects auditory signals and translates the auditorysignals into an electrical signal that varies in amplitude in accordancewith the auditory signals; a driver that amplifies the electrical signalto provide an amplified electrical signal; a coil formed from a printedcircuit board trace on a printed circuit board; a magnetostrictive filmsubstantially covering the coil on the printed circuit board thatchanges size in response to a magnetic field generated by the amplifiedelectrical signal that is applied to the coil and generates auditoryvibrations corresponding to the amplitude of the amplified electricalsignal that assist the users in hearing the auditory signals.

An embodiment of the present invention may therefore further comprise amethod of assisting an individual with auditory comprehension andhearing of audible signals using a hearing device comprising: providinga diaphragm comprising a plastic and magnetostrictive material; forminga wire in a coil; mounting the diaphragm adjacent to the coil;generating an electrical signal from the auditory signal; applying theelectrical signal to the coil that causes the magnetostrictive materialto change size in response to a magnetic field generated by theelectrical signal applied to the coil so that the magnetostrictivematerial generates auditory vibrations to assist the individuals withthe auditory comprehension of audible sounds.

An embodiment of the present invention may therefore further comprise ahearing device that assists users having impaired auditory comprehensionand hearing comprising: a detector that detects audible signals andtranslates the audible signals into an electrical signal that varies inamplitude in accordance with the audible signals; a driver thatamplifies the electrical signal to provide an amplified electricalsignal; a coil formed from a conductive wire that is connected to thedriver to receive the amplified electrical signal and generate amagnetic field in response to the electrical signal that varies inamplitude in accordance with the amplitude of the electrical signal; afirst diaphragm comprising a plastic and magnetostrictive material, thediaphragm mounted adjacent to the coil so that magnetic flux lines ofthe magnetic field cause the magnetostrictive material to change sizeand generate auditory vibrations in the diaphragm that correspond to theamplitude of the electrical signal that assist the users incomprehending and hearing the audible signals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of one embodiment of a conductivewire covered with a magnetostrictive covering.

FIG. 2 is a schematic illustration of another embodiment of a conductivewire covered with a magnetostrictive covering.

FIG. 3 is a schematic illustration of a multi-coil winding that usesconductive wires having magnetostrictive covering.

FIG. 4 is a schematic illustration of one embodiment of a printedcircuit board device.

FIG. 5 is a schematic illustration of an embodiment of amagnetostrictive film.

FIG. 6 is a schematic illustration of another embodiment of amagnetostrictive film.

FIG. 7 is a schematic illustration of another embodiment of a printedcircuit board device.

FIG. 8 is a schematic illustration of an embodiment of a hearing device.

FIG. 9 is a schematic illustration of another embodiment of a hearingdevice.

FIG. 10 is a perspective view of another embodiment.

FIG. 11 is a side view of the embodiment of FIG. 10.

FIG. 12 is a cutaway view of another embodiment.

FIGS. 13-24 are graphs of test results.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 is a schematic illustration of a conductive wire 100 that iscovered by a magnetostrictive covering 102. The magnetostrictivecovering can comprise any of the magnetostrictive materials. Forexample, the magnetostrictive covering 102 may be a magnetostrictivefilm, an amorphous metallic alloy, a metallic glass, a metallic ribbon,a glassy metal, a ribbon alloy, a shaped memory alloy, a metallic foil,a metallic polymer or other materials and shapes. In addition, metallicpolymers can be extruded over the conductive wire 100 using standardextrusion techniques for placing covers over wires to form themagnetostrictive covering 102. Magnetostrictive materials convertmagnetic energy into kinetic energy, or the reverse, and are typicallyused to build actuators and sensors. Magnetostrictive properties can bequantified by the magnetostrictive coefficient (L), which is thefractional change in length as the magnetization of the materialincreases from zero to a saturation value.

Cobalt exhibits the largest room temperature magnetostriction of a pureelement at 60 microstrain. Among alloys, the highest knownmagnetostriction is exhibited by Terfenol-D. Terfenol-D is representedas ThxDyl-xFe2. Terfenol-D exhibits approximately 2,000 microstrains ina field of 2 kOe (160 kA/m) at room temperature. Terfenol-D is the mostwidely used magnetostrictive material. As indicated above, it can beused as an alloy or mixed with polymers that can be extruded over theconductive wire 100. Terfenol-D can also be mixed with polymers to forma film, as disclosed in more detail below.

As shown in FIG. 1, the magnetostrictive covering 102 has a certainthickness. The response of the magnetostrictive covering 102 isdependent, at least to some extent, upon the thickness of themagnetostrictive covering 102. In other words, the time response and theamount the magnetostrictive covering 102 change in size depend upon thethickness of the magnetostrictive covering 102.

FIG. 2 illustrates another embodiment of a conductive wire that iscovered by a magnetostrictive covering 202. As shown in FIG. 2, themagnetostrictive covering 202 is thinner than the magnetostrictivecovering 102 illustrated in FIG. 1. Magnetostrictive covering 202 has aquicker response time than the magnetostrictive covering 102 of FIG. 1as a result of the fact that the magnetostrictive covering 202 isthinner. The delayed response of the magnetostrictive covering 102 isutilized in accordance with the various embodiments disclosed herein.Layering of 1 mm films can provide 8 mm film which can be effectivelyused on a diaphragm. Also, any desired thickness of the magnetostrictivematerial, that is mixed with a polymer, can be extruded directly on adiaphragm. Further, the magnetostrictive material can be mixed with apolymer that is suitable to function as a diaphragm, so that thediaphragm can be extruded or molded with the magnetostrictive materialdisposed in the diaphragm.

FIG. 3 is a schematic illustration of another embodiment. As shown inFIG. 3, a multi-coil winding 300 is made from a wire 302 that is coveredwith a magnetostrictive covering or coating 304. The magnetostrictivecovering 304 reacts to the magnetic field that is created by the currentthat passes through wire 302, which is applied to the wire 302 by theelectronics package 306. Electronics package 306 can include any type ofelectronics including digital signal processors, microprocessors, activefilters, amplifiers, etc. The magnetic field generated by the multi-coilwinding 300 causes the magnetostrictive covering 304 to change size. Themulti-coil winding 300 with the magnetostrictive coating 304 can be usedfor hearing devices, as explained more fully below. The advantage ofusing a conductive wire, such as a copper wire, is that a copper wire,or similar wire, such as a silver wire, has very low resistance and isvery efficient in generating a magnetic field. Materials that aremagnetizable, such as ferrite based materials, have greater resistanceand are therefore less efficient. Because of the small size of mosthearing devices, efficiency of the system is important. Very smallbattery packs must be used in such small devices, which require higherefficiency. Hence, the highly conductive wire, such as a copper wire ora silver wire that is coated with a magnetostrictive material, has theadvantage of generating a magnetic field very efficiently while allowingthe magnetostrictive materials to expand and contract to efficientlygenerate the vibrations that enhance the auditory comprehension of theuser.

Magnetostrictive materials, as indicated above, change shape and producemechanical energy in response to a magnetic field. Conversely, thechange in shape of the magnetostrictive material stores energy so thatwhen the magnetostrictive material returns to its original state, itgenerates a magnetic field that, in turn, will induce current in thecoil. In this fashion, use of magnetostrictive material results in theefficient use of energy and minimal drainage of power from the battery.In that regard, changes in the size of the magnetostrictive material canbe used to generate electricity and run various types of devices thatuse electrical energy. For example, the batteries in a hearing aid canbe charged using this process.

The number of windings utilized in the multi-coil winding 300 that isillustrated in FIG. 3 affects the magnitude of the magnetic field thatis generated by the multi-coil winding 300. It is also believed that thespectral response of the auditory vibrations of the magnetostrictivecoating 304 is affected by the number of windings. Hence, a hearingdevice can be empirically tuned to provide the desired spectral responseby changing the number of windings in the coil.

FIG. 4 is a schematic illustration of a coil 402 that is disposed on aprinted circuit board 400. As shown in FIG. 4, connectors 404, 406 areused to connect to the spiral coil 402. The spiral coil 402 has a spiralshape, rather than a ring shape. In that regard, the term coil is usedherein to include both helicoidal as well as ring coils. Electricalconnections can be made to the connectors 404, 406 to drive a currentthrough the spiral coil 402. The coil 402 and connectors 404, 406 areprinted circuit board traces on the surface of the printed circuit board400. The current that is applied to the coil 402 causes a magnetic fieldto be generated that is substantially perpendicular to the coil 402 atthe surface of the printed circuit board 400. A magnetostrictive film408 is placed over the coil 402. The magnetostrictive film may comprisea polymer film that includes a magnetostrictive material such as, butnot limited to, Terfenol-D that is mixed with the polymer film. Themagnetic field causes the magnetostrictive film 408 to change size inaccordance with the frequency of the electrical signal.

FIG. 5 is a schematic illustration of an embodiment of amagnetostrictive film 500. As shown in FIG. 5, the magnetostrictive film500 is thin. The magnetostrictive film 500 that is illustrated in FIG. 5has a rapid response time in response to the magnetic field that isgenerated by the coil 402.

FIG. 6 is an illustration of another embodiment of a magnetostrictivefilm 600. As shown in FIG. 6, the magnetostrictive film 600 is a thickerfilm than the magnetostrictive film 500 of FIG. 5. The magnetostrictivefilm 600 has a slower response time than the magnetostrictive film 500.In other words, there is a delay in the process of causing themagnetostrictive film 600 to change size in response to the magneticfield generated by the coil 402. A thicker coating on coils, traces orwires also may create a longer delay. Hence, a device, such asillustrated in FIG. 4, that uses magnetostrictive film 600 would have alonger response delay compared to a device, such as illustrated in FIG.4, that uses the thinner magnetostrictive film 500 of FIG. 5.

FIG. 7 is a schematic illustration of another embodiment that uses aprinted circuit board 700 having a coil 704 formed from the printedcircuit board leads. As shown in FIG. 7, a magnetostrictive film 706covers the coil 704. The magnetostrictive film 706 may take variousshapes and have various thicknesses when deposited on the printedcircuit board. In addition, various mixtures and concentrations ofmagnetostrictive materials can be used. As also shown in FIG. 7, theelectronic components 702 are disposed on an opposite side of theprinted circuit board 700. The electronic component 702 can comprisevarious types of components including active filters, microprocessors,digital signal processors, amplifiers, and any other type of componentsused in hearing devices. A multi-layer printed circuit board may be usedin this application to provide connections on an intermediate layer.Connectors 708, 710 provide connections to a battery pack or other powersupply. In this fashion, an electronics package can be provided by theelectronic components 706 that are disposed on the printed circuit board700. Alternatively, the coil 704, magnetostrictive film 706 and theelectronic components 702 can be mounted on the same side of the board.In any event, the electronic components 702 are mounted outside of theperiphery of the coil 704, so as to minimize interference with themagnetic field that is generated by coil 704. Alternatively, themagnetostrictive film 706, illustrated in FIG. 7, may be deposited on asuspended diaphragm over the coil on the printed circuit board 700 toallow greater movement of the magnetostrictive film 706 and providegreater efficiency in the production of sound waves.

FIG. 8 is a schematic illustration of a hearing device 800. The hearingdevice 800 may comprise a hearing aid or hearing aid receiver,collectively referred to as a hearing device, that can be a miniaturizedhearing aid that is disposed either partially within, or fully within,the ear canal of a user. The size of the components allows forconstruction of the hearing device 800 that can be inserted in the earcanal. In that regard, the simplicity of the construction of theembodiment of FIG. 8 provides for a high degree of miniaturization.Further, the hearing device 800 of FIG. 8 can also be disposed in othertypes of hearing devices, such as ear phones, telephones, speakers andother types of devices that generate auditory sound waves. As shown inFIG. 8, the coil 802 has a magnetostrictive coating, such as illustratedin FIGS. 1 and 2. Alternatively, the coil 802 may be wrapped with amagnetostrictive film that comprises a magnetostrictive material, suchas Terfenol-D, that is impregnated in a polymer or other film material.Coil 802 is connected to the electronics package 806 via connectors 804.Electronics package 806 receives an auditory signal from the microphone812, which is amplified by the electronics package 806 and applied viaconnectors 804 to the coil 802. Battery 808 is connected to theelectronics package 806 via connectors 810 to provide power to thehearing device 800. The magnetostrictive material efficiently changesshape in response to a magnetic field that is generated by the currentthat is running through the coil 802. The thickness of themagnetostrictive coating, or the thickness of the film applied aroundthe coil 802, determines the response of the magnetostrictive materialto the current that is applied to the coil 802. The current that isapplied to the coil 802 generates a magnetic field that varies with thenumber of coil windings of the coil 802. The auditory vibrations of thecoil 802 generate sound and auditory vibrational waves that assist theuser in hearing, understanding and enjoying auditory tones. Sound wavesand auditory vibrations are efficiently produced in the magnetostrictivematerial because of the close contact of the magnetostrictive materialwith the coil 802. In addition, many harmonic frequencies are createdbecause of the efficiency of the magnetostrictive coating in generatingauditory vibrations. Again, this is due to the close proximity of themagnetostrictive coating to the wire of the coil 802. For hearingdevices that are inserted in the ear canal, the auditory vibrations ofthe magnetostrictive coating on the coil 802 additionally assist theuser in hearing tonal frequencies. A significantly improved hearingresponse is achieved using the magnetostrictive coating on the coil. Themagnetostrictive material tends to create some noise, which may assistthe user in hearing, as a result of the stochastic resonance. Stochasticresonance may aid the user in the detection and/or enhancement of theauditory signal for easier hearing, identification and enjoyment of theauditory signal. In addition, Barkhausen noise may also assist the userin hearing. Barkhausen noise is the result of a series of sudden changesin the size and orientation of ferromagnetic domains, or microscopicclusters of aligned atomic magnets, that occurs during a continuousprocess of magnetization and demagnetization. In other words,magnetization and demagnetization occurs in minute steps. This creates aclicking or crackling noise because of the discontinuous jumps inmagnetization. This may assist the user in hearing, as a result ofstochastic resonance.

Although inner hair cells are outnumbered approximately four to one byouter hair cells, the inner hair cells gather and transmit the majorityof auditory information that reaches the cerebral cortex. Because thecilia of the inner hair cells are not attached to the tectorialmembrane, stimulation of the inner hair cells most likely results frommotion of the surrounding fluid and basilar membrane. Brownian motion ofthe inner hair cell bundles may provide an optimal noise level thatenhances the sensitivity of the mechanical/electrical transmission toweak acoustic signals. The vibrations provided by the coil 802, as wellas the strong magnetic field that is generated by the coil 802, mayincrease the movement of the fluid in the inner ear, which may increasethe firing of the inner hair cells. Therefore, Brownian motion createdby the embodiment illustrated in FIG. 8 may serve to provide a greateropportunity for signal transmission in a user's ear that has significantouter hair cell damage and inner hair cells intact. In addition, thecoil 802 with the magnetostrictive coating efficiently creates harmonicsof the base frequencies that are very beneficial to the enhancement ofspeech discrimination.

As disclosed in FIGS. 1 and 2, magnetostrictive coatings can be usedthat have different thicknesses and different phase and time delayresponses. The constriction of two different hearing devices 800 can beaccomplished using two different thicknesses of magnetostrictivecoverings. Different thicknesses can be provided using a differentnumber of layers of magnetostrictive material. In this fashion, ahearing device having the thicker magnetostrictive covering 102 willhave a delayed response and a different phase.

Central auditory processing disorder (CAPD) is a condition in which theuser has difficulty processing or interpreting auditory information in aless than optimal listening environment. Individuals with CAPD typicallyhave normal hearing acuity, but are unable to efficiently process orinterpret speech when placed in a minimally noisy environment. Childrenand adults with CAPD often report that they are confused or becomeflustered in busy, listening environments. In classroom environments,the workplace and social gatherings, these individuals often havedifficulty and are confused by different verbal stimuli. CAPD may occurin persons with other disorders, such as autism, ADD/ADHD, sensatoryintegration dysfunction, learning disabilities, speech and languagedeficients, traumatic brain injury or other neurological conditions.CAPD may also appear as an isolated dysfunction. For children and adultswith CAPD, there is evidence of binaural asynchronies (BAs) in theircentral auditory nervous system (CANS). Binaural asynchronies aresynchrony disruptions (delay) in time of auditory input signals to theindividual's ears. Efficient processing of acoustic information relieson binaural interaction or synchronization of auditory inputs betweenthe two ears, which is accomplished by the central auditory nervoussystem in most individuals. For a person with a normal central auditorynervous system function, auditory input between the two ears issynchronized in time. However, for an individual with atypical centralnervous system function, there are asynchronies of various magnitudesthat hinder efficient auditory processing of acoustic information.

By introducing a delay in the auditory signals that are processed by thehearing device 800 by using different thicknesses of magnetostrictivecoverings, binaural asynchronies can be reduced or eliminated, and userscan more effectively distinguish and understand auditory signals. Thisis a result of the fact that the magnetostrictive coverings 102, 202 canbe used to introduce a delay in one of the ears, which may assist theuser in synchronizing auditory signals. Proper delay by using differentthickness of magnetostrictive materials can be established empirically.The delay can also assist users having other neurological disorders,such as traumatic brain injury, Parkinson's disease, multiple sclerosis,etc.

Delay of the sound signal can also be assisted by employing the conceptsof the invention in an ear canal device that has a duct that changes thepropagation length of the sound for each individual ear. In other words,concepts of the various embodiments may be employed in the ear hearingdevice such that propagation lengths are different for each ear. Passivedelay devices can be used separately or in conjunction with the variousembodiments disclosed herein. Passive delay devices are more fullydisclosed in U.S. patent application Ser. No. 11/443,859, filed May 31,2006, entitled “Apparatus and Methods for Mitigating Impairments Due toCentral Auditory Nervous System Binaural Phase-Time Asynchrony,” whichis specifically incorporated herein by reference for all that itdiscloses and teaches.

Comprehension of auditory signals using hearing devices can benegatively impacted by electromagnetic interference. A multi-coilwinding 300, such as shown in FIG. 3, that has a magnetostrictivecovering 102, or a magnetostrictive film 408 over a coil 402, as shownin FIG. 4, is believed to reduce electromagnetic interference. Forexample, appliances that use a large amount of current, such as acomputer monitor, television or other similar device, may createinterference in a hearing device because of the electromagneticinterference of the electrical power signal applied to the appliance.Many hearing aids are constructed using a moving coil apparatus, or abalanced armature apparatus. Each of these devices may function asantennas that pick up the electromagnetic interference that is convertedby the hearing device into an auditory hum that is transmitted to theuser's ear. This may also be the case with electrostatic type of driversthat use electrically charged diaphragms. The embodiments disclosedherein are believed to reduce the electromagnetic interference andprovide a high spectral response that aids users in hearing auditorysignals. Use of magnetostrictive covering on loop systems that interactwith a T coil system in a hearing aid or other hearing device, mayresult in less electromagnetic interference. Another possible source ofinterference that is encountered in standard hearing devices, and notencountered in the embodiments disclosed herein, is interference frommagnetic fields. Many standard hearing devices operate by using a movingcoil mechanism in which a moving coil is attached to a diaphragm that isexposed in a static magnetic field generated by a permanent magnet.Variations of the current that is applied to the coil causes the coil togenerate a magnetic field that interacts with the static magnetic fieldand causes the coil to move on the diaphragm. In this fashion, soundwaves are produced. Various electronic devices generate magnetic fieldsthat perturb the static magnetic field of the permanent magnet in thehearing device. These perturbations in the static magnetic field createinterference in the hearing device. None of the embodiments disclosedherein utilize a static magnetic field that can be perturbed by magneticfields generated by various electronic devices. As a result,interference by magnetic field waves does not occur in the embodimentsdisclosed herein.

FIG. 9 is a schematic illustration of another embodiment of a hearingdevice 900. Hearing device 900 is a device that is also amenable tominiaturization because of its compact size. As shown in FIG. 9, amagnetostrictive film 902 is deposited over coil 904. Coil 904 is a coilthat may be made from the printed circuit board traces of printedcircuit board 906. Electronic components 908 may be disposed on theother side of the printed circuit board 906 from coil 904 or on the sameside. Electronic components 908 may be disposed around the periphery ofthe printed circuit board, or to one side of the circuit board, so thatthe magnetic waves generated by the coil 904 are not interrupted by theelectronic components 908. The printed circuit board 906 and theelectronic components 908 are connected to a microphone 912 that detectsauditory signals. These auditory signals are amplified and applied tothe coil 904. Current in the coil 904 generates a magnetic field thatcauses the magnetostrictive film 902 to change size and generateauditory vibrations. The auditory vibrations of the magnetostrictivefilm 902 produce sound waves that are efficiently transmitted to theuser. In addition, the auditory vibrations of the magnetostrictive film902 may be transmitted through the tissue in the user's ear to furtherassist in hearing and comprehension. Battery 910 supplies power to theelectronic components 908 on the printed circuit board 906 viaconnectors 914.

The hearing device 900, illustrated in FIG. 9, may be a hearing aid thatis disposed in the outer ear, headphones, a telephone, a speaker or manyother types of hearing devices. Since the magnetostrictive film 902 isplaced directly over the coil 904, a high degree of efficiency isachieved in generating auditory vibrations. As a result, multipleharmonic frequencies are generated, which also assists the user incomprehending the auditory signals detected by the microphone 912. Ofcourse, some auditory frequencies may be amplified to a greater extentthan others, in accordance with the standard practice of designing ahearing device for a particular user. In general, however, the efficientoperation and generation of multiple harmonic frequencies, as well asthe generation of stochastic resonances by both hearing device 800 andhearing device 900, greatly increases the auditory comprehension,understanding and enjoyment by the user. Of course, the variousembodiments disclosed herein can be disposed in any type of hearingdevice including headphones, speakers, ear pods, etc. and could be usedby individuals who do not have hearing loss and do not have hearingcomprehension problems, but, rather, like to enjoy an audio response andtake full advantage of the attributes of various embodiments disclosedherein. Further, each of the devices disclosed herein can beencapsulated in a standard package for connection to a device such as aheadphone, speaker, etc. In that regard, the encapsulated packages canbe sold as modular devices that can be employed in any desired fashion,such as any type of hearing device, including hearing aids, headphones,speakers, etc.

FIGS. 10 and 11 disclose a magnetostrictive diaphragm design for hearingdevices. FIG. 10 is a perspective view of the magnetostrictive diaphragmdesign 1000, while FIG. 11 is a side view. As shown in FIG. 10, coil1002 is attached to lead wires 1004, 1006 that apply electrical signalsto the coil 1002 that are representative of auditory signals. The coil1002 may comprise a conductive wire such as conductive wire 200 that issurrounded by magnetostrictive covering 2002. Alternatively, coil 1002may be wrapped in a magnetostrictive film or over-molded with amagnetostrictive plastic over-molding. Further, coil 1002 may contain nomagnetostrictive materials. Coil 1002 is placed adjacent a ring 1012, asdisclosed in both FIGS. 10 and 11. Ring 1012 is a support ring thatsupports a magnetostrictive diaphragm 1008 that is suspended from thering by a flexible membrane 1014. Magnetostrictive diaphragm 1008 can beformed from a thin polymer or plastic material that is embedded or mixedwith magnetostrictive materials. Cone 1010 is an optional feature thatcan be used to direct the audio signals that are generated by themagnetostrictive diaphragm 1002.

In operation, the coil 1002 of FIGS. 10 and 11 generates a magneticfield that varies with the application of the electrical signal that isapplied to lead wires 1004, 1006. The magnetic field penetrates the coiland the magnetostrictive diaphragm 1008 as shown by the exemplarymagnetic flux line 1018. As the magnetic field generated by the coil1008 varies in response to the electrical signal applied to lead wires1002, 1006, the magnetostrictive materials change size which causesdiaphragm 1008 to move and push the surrounding air to create soundwaves. In other words, the magnetostrictive diaphragm 1008 includesmagnetostrictive materials that change size in the magnetic fieldcreated by the coil 1002 and cause the magnetostrictive diaphragm 1008to move response to the magnetic field. In addition, Ferrofluid, whichis produced by Ferrotec Corporation, can also be coated on themagnetostrictive diaphragm 1008 to further assist in driving themagnetostrictive diaphragm 1008. Ferrofluid is available from FerrotecCorporation located in Bedford, N.H., and San Jose, Calif.

FIG. 12 is a cutaway view of an embodiment of a headphone unit 1200. Asshown in FIG. 12, the headphone unit 1200 includes a speaker 1202, aheadphone coil 1204 and a headphone magnet 1206. These are the standardcomponents that are found in typical headphones. As also shown in FIG.12, a multicoil winding 1210 is embedded in a mylar covering 1208 andplaced over the rear portion of the headphone unit adjacent theheadphone magnet 1206 and the headphone coil 1204. The mylar covering1208 can be friction fit to the back of the headphone unit or can beattached by other mechanical means, such as by adhesives, etc. Aplurality of layers of magnetostrictive film 1212 are then placed overthe mylar covering 1208 and the multicoil winding 1210. Themagnetostrictive film may comprise a polymer that is mixed withparticles of magnetostrictive material. In one embodiment, each layer ofmagnetostrictive film has a thickness of 1 mil. The headphone wire 1216that is attached to the headphone coil 1204 can be clipped and attachedto multicoil winding wire 1218. Multicoil winding wire 1220, which is atthe other end of the multicoil winding 1210, can then be connected tothe drive source for the headphone unit 1200. The headphone wire 1214,which is at the other end of the headphone coil 1204, can remainattached to the driving source. In this manner, multicoil winding 1210is placed in series with the headphone coil 1204.

The headphone unit 1200 that is illustrated in FIG. 12 providesexcellent speech discrimination for both hearing impaired users andusers with no hearing loss. Tests on similar headphones are describedbelow, which show increased speech discrimination using similarlymodified headphone units. Of course, any type of auditory speaker systemcan be modified in this manner, including headphones that are used intelephones, ear pods, hearing aids, speakers and similar devices. Themultiple layers of magnetostrictive film 1212 also assist in blockingelectromagnetic interference, which may be generated by noisyappliances, computers, cell phones, etc.

Tests were performed using headphones that have been modified by placinga magnetostrictive polymer film over the headphone coil similar to theembodiment of FIG. 12. Groove headphones, model TM-707v, available fromGroove Industries Co. Ltd, Rm703 A, Huangdu Plaza, Yitian Rd, Futian,Shenzhen, China, were modified to determine speech discrimination. Theear assembly cover of the headphone was pried open to expose the speakerassembly. A circle of thin black foam padding was removed and eightpieces of 1 MIL amorphous magnetostrictive film, that were cut into11/16″ squares, were stacked together and enclosed with electrical tape.The stacked pieces were then tapes to the speaker assembly of theheadphone with a metal assembly placed on top of the tape strip. A 100turn, 36 G wire coil assembly was then placed on top of the metallayers. The red wire from the speaker was then removed and one end ofthe coil was attached to the speaker where the red wire was removed. Theother coil wire was then attached to the red wire that was removed fromthe speaker. The earpiece assembly was then reassembled and the otherearpiece was modified in the same manner.

Subjects were tested to determine potential benefit from the retrofittedheadphones. Speech discrimination measurements were made with both themodified headphones and unmodified headphones in both quiet and noisyenvironments. One of the most challenging areas for audio and assistivedevices for those with hearing loss involves the enhancement of speechunderstanding in the presence of noise. Understanding speech in noisecontinues to be the most prevalent complaint of individuals usinghearing aids. Designing affordable and easily embedded technology invarious audio systems, such as headphones, telephones and hearing aidsto address enhancement of speech understanding in noisy environmentsprovides great assistance to many individuals.

The subjects in the testing of the modified headphones were 75 nativeEnglish speaking male and female subjects from eight years to adult.Participants were recruited from Northern Colorado. The 75 participantswere broken into the following groups: 1) normal hearing; 2) hearingloss; 3) central auditory processing disorder. All participants wereseparated into these groups based upon their pure tone findings and, forthose included in the central auditory processing disorder group, bysimple auditory processing testing. Participants with hearing loss hadhearing thresholds span levels of impairment from a mild degree throughprofound. Various types of hearing loss and configurations of impairmentwere included in the study.

The participants were evaluated using strict audiologic controls. Allaudiologic testing procedures were conducted in a double walled, IAC,soundproof room. A Grason-Stadler (GSI-61) diagnostic audiometer wasused to present test items to participants via TDH-50 electrodynamicearphones (10 ohm, mounted in MX/41 AR cushions). The audiometer wascalibrated in accordance with ANSI (1989 S3.6) specifications before thecollection of data. Speech stimuli for monosyllabic word testing wasplayed on a CD player and passed through the speech circuit of theGSI-61 diagnostic audiometer. Speech reception thresholds (SRT) wereestablished using the W-1 CID Spondee word list, and speechdiscrimination scores in quiet were obtained using Campbell's wordlists. Campbell's word lists are standardized and are commonly used inauditory studies. The pattern of each monosyllabic word was of theconsonant-vowel-consonant type. Impedance audiometry was also performedusing the Grason-Stadler, Model TympStar impedance unit. Tympanometrywas administered for both ears. Three targeted headphones (TH-50 Groove,Model 707 non-retrofitted headphone, Groove, Model 707 retrofittedheadphone) were introduced during the final phase of testing. Theseincluded standard diagnostic TDH-50 headphones, Groove, Model 707,headphones and Groove, Model 707, retrofitted headphones with newhearing technology. All headphones were calibrated according to ISO(1964) and ANSI (1969) standards. Correction factors were employedthroughout testing for each headphone to maintain consistency in outputfor all headphones and test stimuli. NU-6 phonetically balances wordlist (Tillman & Carhart 1966) (Lists A1, A2, A4, B1, B2 and B4) wereused to determine single words speech discrimination scores in noise.These words were presented via a CD player using a CD recorded byAuditec of St. Louis. Words were presented through the targetedheadphones via the Grason-Stadler, Model GSI-61, diagnostic audiometer.These words were presented at 40 dB SL re pure tone average withsignal-to-noise ratio of +6 using speech band noise presentedipsilaterally. These word lists are standardized and are commonly usedin auditory studies. The pattern of each monosyllabic word was of theconsonant-vowel-consonant type. Results of this testing are shown inFIGS. 13 and 14.

FIG. 13 discloses a graph 1300 of the mean speech discrimination scoresin noise for individuals with hearing loss using three differentheadphones. As shown in FIG. 13, the retrofitted headphones providedmuch better speech discrimination.

FIG. 14 is a graph 1400 of the mean speech discrimination scores innoise for individuals with normal hearing using three differentheadphones. As shown in FIG. 14, the retrofitted headphones providedmuch greater speech discrimination for users with normal hearing.

FIGS. 15-24 are graphs of additional test results on the HPA-1000Cnon-retrofitted headphone and the HPA-1016C retrofitted headphone. FIGS.15 and 16 show impedance measurements of the headphones versusfrequency. FIG. 15 is a graph 1500 of the impedance of an HPA-1000Cheadphone that is not retrofitted. FIG. 16 is a graph 1600 of theimpedance of an HPA-1016C headphone with the retrofitted technology. Theimpedance measurements are of interest since these graphs show how muchof a load each headphone places on the circuit driving the headphone.The lower the impedance of the headphone, the greater the load on thedriving circuit. FIG. 17 is a graph 1700 that shows the second andfourth even order harmonic distortion of the HPA-1000C headphones thathave not been retrofitted using a 63 mV drive. FIG. 18 is a graph 1800that shows the third and fifth odd order harmonic distortions of theHPA-1000C non-retrofitted headphones using a 63 mV drive. FIG. 19 is agraph 1900 that shows the second and fourth even order distortion of theHPA-1016C retrofitted headphones, using a 63 mV drive. As shown in FIG.19, the harmonic distortion of the even orders is much greater for theretrofitted headphones than the even order distortion illustrated inFIG. 17. FIG. 20 is a graph 2000 that shows the third and fifth oddorder harmonic distortion of the HPA-1016C retrofitted headphones usinga 62 mV drive. FIG. 20 shows much larger harmonic distortions for theretrofitted headphones than the non-retrofitted headphones, for thethird and fifth odd order harmonics, illustrated in FIG. 18. FIG. 21 isa graph 2100 of the total harmonic distortion of the HPA-1000Cnon-retrofitted headphones using a 62 mV drive. FIG. 22 is a graph 2200of the total harmonic distortion plus noise of the HPA-1000Cnon-retrofitted headphones using a 62 mV drive. FIG. 23 is a graph 2300of the total harmonic distortion of the HPA-1016C retrofitted headphonesusing a 62 mV drive. As shown in FIG. 23, there is substantially greatertotal harmonic distortion of the retrofitted headphones than thatillustrated in FIG. 21, especially at lower frequencies. FIG. 24 is agraph 2400 of the total harmonic distortion plus noise of the HPA-1016Cretrofitted headphones using a 62 mV drive. Again, there is asubstantially larger amount of total harmonic distortion illustrated inFIG. 24, as compared to that shown in FIG. 22, especially at lowerfrequencies. Hence, these tests illustrate that harmonic distortion isincreased with the modified headphones which may assist in the processof speech discrimination. All of the measurements were made with agold-Line TEF 25 analyzer. Level calibration was performed by a Bruel &Kjaer 4231 calibrator. Acoustic measurement was performed by a GeneralRadio (GenRad) 1560-T83 earphone coupler with a 1987-2050 adapter. Themicrophone used was a Sound First SF111 Type 1 microphone. Theheadphones were driven by a Whirlwind PA-1 headphone amplifier set forunity gain. The headphone amplifier has an output impedance of 10 ohms.

The foregoing description of the invention has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed, andother modifications and variations may be possible in light of the aboveteachings. The embodiment was chosen and described in order to bestexplain the principles of the invention and its practical application tothereby enable others skilled in the art to best utilize the inventionin various embodiments and various modifications as are suited to theparticular use contemplated. It is intended that the appended claims beconstrued to include other alternative embodiments of the inventionexcept insofar as limited by the prior art.

1. A method of assisting an individual with auditory comprehension ofaudible signals using a hearing device comprising: coating a conductivewire with a magnetostrictive coating; forming said wire in a coil;generating an electrical signal from said auditory signal; applying saidelectrical signal to said coil that causes said magnetostrictive coatingto change size in response to said electrical signal so that saidmagnetostrictive coating generates auditory vibrations to assist saidindividuals with said auditory comprehension of audible sounds.
 2. Themethod of claim 1 further comprising: providing separate hearing devicesfor each ear of said individual; coating conductive wires of saidhearing devices with magnetostrictive coatings that have differentthicknesses so that said separate hearing devices have differentresponse times that assist individuals having CAPD, hearing loss and/orother neurological disorders, including traumatic brain injury,Parkinson's disease and multiple sclerosis.
 3. The method of claim 1wherein electricity is generated in said wire when said magnetostrictivecoating returns to an original size to assist in charging batteries insaid hearing device.
 4. A hearing device that assists users havingimpaired auditory comprehension comprising: a detector that detectsaudible signals and translates said audible signals into an electricalsignal that varies in amplitude in accordance with said audible signals;a driver that amplifies said electrical signal to provide an amplifiedelectrical signal; a conductive wire formed in a coil that is connectedto said driver to receive said amplified electrical signal and generatea magnetic wave in response to said electrical signal that varies inamplitude in accordance with said amplitude of said electrical signal; afirst magnetostrictive coating substantially surrounding said conductivewire that changes size in response to said electrical signal andgenerates auditory vibrations corresponding to said amplitude of saidelectrical signal that assist said users in comprehending said audiblesignals.
 5. The hearing device of claim 4 further comprising: a secondhearing device that has a second magnetostrictive coating that isthicker than said first magnetostrictive coating so that said secondhearing device has a delayed response to assist users having CAPD and/orother neurological disorders.
 6. A method of assisting an individualwith auditory comprehension of audible signals using a hearing devicecomprising: forming a coil from a printed circuit board trace on aprinted circuit board; covering said coil formed on said printed circuitboard with a magnetostrictive film; generating an electrical signal fromsaid auditory signal; applying said electrical signal to said coil thatcauses said magnetostrictive film to change size in response to saidelectrical signal so that said magnetostrictive film generates auditoryvibrations to assist said individual with said auditory comprehension ofaudible signals.
 7. The method of claim 6 further comprising: providinga second hearing device for another ear of said individual; coating asecond coil on a second printed circuit board of said second hearingdevice with a second magnetostrictive film that has a second thicknessthat is different from a thickness of said magnetostrictive coating sothat said second hearing device has a different response time thatassists said individual in comprehension of said audible signals.
 8. Ahearing device that assists users having impaired auditory comprehensioncomprising: a microphone that detects auditory signals and translatessaid auditory signals into an electrical signal that varies in amplitudein accordance with said auditory signals; a driver that amplifies saidelectrical signal to provide an amplified electrical signal; a coilformed from a printed circuit board trace on a printed circuit board; afirst magnetostrictive film substantially covering said coil on saidprinted circuit board that changes size in response to a magnetic fieldgenerated by said amplified electrical signal that is applied to saidcoil and generates auditory vibrations corresponding to said amplitudeof said amplified electrical signal that assist said users incomprehending said audible signals.
 9. The hearing device of claim 8further comprising: a second hearing device that has a secondmagnetostrictive film that is thicker than said first magnetostrictivefilm so that said second hearing device has a delayed response to assistusers, having CAPD and/or other neurological disorders, in comprehendingsaid audible signals.
 10. A method of assisting an individual withhearing an auditory signal using a hearing device comprising: coating aconductive wire with a magnetostrictive coating; forming said wire in acoil; generating an electrical signal from said auditory signal;applying said electrical signal to said coil that causes saidmagnetostrictive coating to change size in response to a magnetic fieldgenerated by said coil in response to said electrical signal so thatsaid magnetostrictive coating generates auditory vibrations that assistsaid individual with hearing said auditory signal.
 11. The method ofclaim 10 wherein interference of electromagnetic waves is reduced.
 12. Ahearing device that assists users having impaired auditory functioncomprising: a microphone that detects auditory signals and translatessaid auditory signals into an electrical signal that varies in amplitudein accordance with said auditory signals; a driver that amplifies saidelectrical signal to provide an amplified electrical signal; aconductive wire formed in a coil that is connected to said driver toreceive said amplified electrical signal and generate a magnetic fieldin response to said electrical signal that varies in amplitude inaccordance with said amplitude of said electrical signal; a firstmagnetostrictive coating substantially surrounding said conductive wirethat changes size in response to said magnetic field and generatesauditory vibrations corresponding to said amplitude of said amplifiedelectrical signal that assist said users in hearing said auditorysignals.
 13. A method of assisting an individual with hearing auditorysignals using a hearing device comprising: forming a coil from a printedcircuit board trace on a printed circuit board; covering said coilformed on said printed circuit board with a magnetostrictive film;generating an electrical signal from said auditory signal; applying saidelectrical signal to said coil that causes said magnetostrictive film tochange size in response to said electrical signal so that saidmagnetostrictive film generates auditory vibrations to assist saidindividuals with hearing said auditory signals.
 14. The method of claim13 wherein interference of electromagnetic waves is reduced.
 15. Ahearing device that assists users having impaired hearing comprising: adetector that detects auditory signals and translates said auditorysignals into an electrical signal that varies in amplitude in accordancewith said auditory signals; a driver that amplifies said electricalsignal to provide an amplified electrical signal; a coil formed from aprinted circuit board trace on a printed circuit board; amagnetostrictive film substantially covering said coil on said printedcircuit board that changes size in response to a magnetic fieldgenerated by said amplified electrical signal that is applied to saidcoil and generates auditory vibrations corresponding to said amplitudeof said amplified electrical signal that assist said users in hearingsaid auditory signals.
 16. The hearing device of claim 3 whereinelectromagnetic interference is reduced by said hearing device.
 17. Amethod of assisting an individual with auditory comprehension andhearing of audible signals using a hearing device comprising: providinga diaphragm comprising a plastic and magnetostrictive material; forminga wire in a coil; mounting said diaphragm adjacent to said coil;generating an electrical signal from said auditory signal; applying saidelectrical signal to said coil that causes said magnetostrictivematerial to change size in response to a magnetic field generated bysaid electrical signal applied to said coil so that saidmagnetostrictive material generates auditory vibrations to assist saidindividuals with said auditory comprehension of audible sounds.
 18. Themethod of claim 17 further comprising: providing separate hearingdevices for each ear of said individual; providing diaphragms forhearing devices for each ear of said individual that have diaphragmsthat have different thicknesses so that said separate hearing deviceshave different response times that assist individuals having CAPD and/orother neurological disorders.
 19. A hearing device that assists usershaving impaired auditory comprehension and hearing comprising: adetector that detects audible signals and translates said audiblesignals into an electrical signal that varies in amplitude in accordancewith said audible signals; a driver that amplifies said electricalsignal to provide an amplified electrical signal; a coil formed from aconductive wire that is connected to said driver to receive saidamplified electrical signal and generate a magnetic field in response tosaid electrical signal that varies in amplitude in accordance with saidamplitude of said electrical signal; a first diaphragm comprising aplastic and magnetostrictive material, said diaphragm mounted adjacentto said coil so that magnetic flux lines of said magnetic field causesaid magnetostrictive material to change size and generate auditoryvibrations in said diaphragm that correspond to said amplitude of saidelectrical signal that assist said users in comprehending and hearingsaid audible signals.
 20. The hearing device of claim 19 furthercomprising: a second hearing device that has a second diaphragm withmagnetostrictive material that is thicker than said first diaphragm sothat said second hearing device has a delayed response to assist usershaving CAPD and/or other neurological disorders.